I just got home from the range where I shot a loading in my latest 22-250 Remington Varminter that I have come to "rely" on!
And it shot VERY well again for me today, in the third straight Varmint Rifle I have tried it in.
The first Varminter I tried this loading in was a Remington XR-100 and I was very pleased with the Rifle and the loading. Then I tried this load in a a Remington 700 VLS with equally impressive results, and now today I used the loading in my new Ruger #1-V SS.
My 22-250 Remington loading consists of the following components:

Berger 52 grain bullets
Winchester brass
Federal 210 M primers
And a right at maximum load of Varget powder

The reason I am not going to post the powder charge is because in one major reloading manual my chosen load is 0.3 grains over their published maximum.
Several other loading manuals list my load as near but under maximum.
Anyway I have used this loading for Prairie Dogs in temperatures much higher than when I developed the load and tested the load in my first two Rifles.
No signs of pressure at any time.
I am not especially well versed on what powders are and are not "temperature sensitive", but this load showed NO pressure signs either when developed (during the cold of winter) or when shot afield (during the heat of summer).
My chronograph results with my first two 22-250's shooting this load were right at 3,700 FPS!
So this loading has been both accurate AND fast, for me.
My first two Rifles have 26" barrels but this new heavy barrel stainless Ruger #1-V only has a 24" barrel.
I'll chronograph this load in this Rifle next time I take it to the range.
These wonderful Berger 52 grain bullets, by the way, are real "performers" on Prairie Dogs and Rock Chucks at these velocities!
If you haven't tried the Berger 52's in your 22-250 or 220 Swift be sure to give them a try.
They are a little bit pricey but I think well worth the money.
Long live the 22-250!
Hold into the wind
VarmintGuy

Holy crap! Is that a paragraph?

I guess I'll never know as I aint gonna read through all that to find out.

Varget has been pretty temperature stable for me. I also use it in my 22-250 along with my 308 Winchester. That's a big reason I use it; I develop a lot, if not most of my loads in the early spring when temps are 40-60 degrees. I don't want pressure issues when it's 90-100 degrees out in the summer. I really like Hodgdon's "Extreme" powders for temperature stability and consistency.

Rlee2500: And I develop a lot of my loads in the winter after Big Game season is over.
I often shoot on days when it is from 5 to 20 degrees above zero.
Then I take those loads out in the field come summer time!
Somewhat worrisome.
I went to replenish my Varget powder supply this morning and the Varget powder is somewhat pricier than most other powders - maybe its the shop or the popularity of Varget or the fact that it is an "extreme powder"?
You've got to pay to play they say.
I just know Varget has sure been a GOOD powder for me.
Hold into the wind
VarmintGuy